void test_T2s(Tensor1<double,3> &t1_1, const Tensor1<double,3> &t1_2,
	      Tensor2<double,3,3> &t2_1, const Tensor2<double,3,3> &t2_2,
	      Tensor2_symmetric<double,3> &t2s_1,
	      const Tensor2_symmetric<double,3> &t2s_2,
	      const Tensor2_symmetric<double,3> &t2s_3);
